Hydraulic control in monoblock structure for lifting and lowering a load with at least two electromagnetically actuatable proportional distributing valve elements

US5839345A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hartmut Sandau · Schwieberdingen, DE
• Werner Schumacher · Asperg, DE
• Rainer Trucksess · Lambach, DE
• Holger Lueues · Bietigheim-Bissingen, DE

Key dates

• Filing date: Jun 23, 1997
• Grant date: Nov 24, 1998
• Expiry date: Jun 23, 2017

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F15B2211/7052
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A hydraulic circuit in a monoblock structure for lifting and lowering a load has at least two electromagnetically actuatable proportional distributing valve elements, a check valve, a pressure balance for load-independent lifting of the load as an input element, a housing accommodating at least some of the elements and having at least one pump connection, at least one consumer connection, and at least one return connection, the proportional distributing valve elements being disposed parallel to one another, electromagnetic drives seated side-by-side on a same side and at a same height, the pressure balance having a piston which is disposed coaxially next to a longitudinal slide of a first one of the proportional distributing valve elements in a bore that guides and supports both the valve elements, the longitudinal slide of the first proportional distributing valve elements being spring-loaded, and at least one component for adjusting a prestressing and bracing of a spring on the housing of a control penetrating the piston of the pressure balance.